This application relates to an electronic device capable of sensing rotary and push-type user inputs.
The button-wheel is a device that can sense continuous rotation about a rotational axis as well as switch action in a direction perpendicular to the rotational axis; it increases user efficiency by enabling users to transmit two distinct types of input to a host machine while interacting with only one device.
Button-wheels are also related to knob-buttons that include rotational knobs that support a switching function perpendicular to the axis of rotation. These knob-buttons typically actuate switches through movement of knobs and knob mountings.
Button-wheels are currently prevalent in cursor control devices such as computer mice. Most conventional mouse button-wheels possess a configuration and switch actuation method similar to the one described in U.S. Pat. No. 5,912,661 to Siddiqui and illustrated in FIG. 1. The button-wheel is built on a circuit board 28 that physically supports both mechanical and electrical components while placing button-wheel sensors in electrical communication with the rest of the mouse. The wheel 22 has a diameter that is much greater than its width. Wheel 22 is mounted on a relatively rigid shaft 64 that is much longer than wheel 22""s width. Shaft 64 is held in place by two bearings that allow shaft 64 to rotate about its axis, but not translate along this axis.
A first bearing 32 further constrains a first end 991 of shaft 64 from moving in the other two translational directions; however, first bearing 32 does not prevent shaft 64 from tilting about first bearing 32. A second bearing is formed by two distinct components: a spring 58 that biases second end 992 and wheel 22 toward the user, and a slotted shape 34 that constrains second end 992, such that it can translate only within the slot cutout. The slot cutout is a straight slot that is perpendicular to the axis of shaft 64; this limits the motion of second end 992 to almost directly towards or away from circuit board 28. Shaft 64 also has a collar-type feature 50, located near slotted shape 34, that hovers above a button 51 of switch 52.
With this configuration, when the user pushes on wheel 22, shaft 64 tilts about first bearing 32 and sweeps a wedge-shaped section of a circle. Shaft 64 compresses spring 58, and collar 50 touches and depresses button 51 to actuate switch 52. The magnitude of shaft 64""s tilt is limited by the length of the slot in slotted shape 34, the full compression distance of spring 58, and the actuation distance of button 51. Spring 58 and button 51 together generate the desired user tactile and auditory feedback for this switch actuation action. Conductive paths along the circuit board 28 route the button signals to the mouse electronics (not shown).
Also on shaft 64 is an encoder disc 44, which forms a complete optical rotary encoder with an optical emitter 46 and an optical detector 48. Shaft 64 further contains a series of grooves that interact with a ratchet-like feature 42 to form a detent mechanism. When the user rotates wheel 22, the encoder assembly (formed by encoder disc 44, optical emitter 46, and optical detector 48) produces digital signals that are typically quadrature in nature. The detent mechanism (formed by grooves 40 and ratchet 42) generates the desired user tactile and auditory feedback for the rotational motion. Conductive paths along the circuit board 28 route the encoder signals to the mouse electronics (not shown).
Variations on this general button-wheel idea are known in the art. The simplest variations involve using different types of the basic components (such as mechanical encoders instead of optical encoders, ball detents instead of grooves and ratchets, and lever-type switches instead of pushbutton switches) and shifting their relative location (such as moving switch 52 to the other side of slotted shape 34 or placing encoder disc 44 to the opposite side of first bearing 32).
Slightly more complex variations involve combining many components into one integral unit. U.S. Pat. No. 6,188,393 to Shu, U.S. Pat. No. 6,157,369 to Merminod et al., and U.S. Pat. No. 6,014,130 to Yung-Chou describe devices in which the encoder disc (analogous to encoder disc 44 of the Siddiqui patent ""661) is constructed as part of a wheel (analogous to wheel 22 of the Siddiqui patent ""661). The devices outlined in U.S. Pat. No. 6,285,355 to Chang and U.S. Pat. No. 5,808,568 to Wu combines at least part of the detent mechanism with the encoder disc and the wheel (analogous to grooves 40, ratchet 42, encoder disc 44, and wheel 20 of the Siddiqui patent ""661) to generate one integral unit.
Other button-wheel variations involve different switch actuation actions. For example, U.S. Pat. No. 5,473,344 to Bacon et al. describes another tilting-shaft switch actuation method in which an additional slotted shape is utilized, and U.S. Pat. No. 5,446,481 to Gillick et al. discloses an hourglass-shaped wheel that tilts about its center to actuate switches located under either side of the hourglass-shaped wheel. These alternative tilting-shaft devices are more complex and require more components than the device presented in Siddiqui patent ""661.
In addition to the tilting switch actuation action, alternatives that include semi-tilting switch actuation mechanisms also exist. Both U.S. Pat. No. 6,246,392 to Wu and U.S. Pat. No. 6,188,389 to Yen disclose button-wheels in which the two bearings supporting the wheel shaft include slotted shapes that have slots which help guide the motion of the wheel shaft; the devices disclosed in the Wu patent ""392 and the Yen patent ""389 bias the wheel shaft toward the user with one single spring located on one side of the wheel. The Merminod patent describes a different system that utilizes only one slotted shape; the end of the wheel opposite to the slotted shape is attached to a formed spring, and can move in a manner limited by the deflection of the spring. Since all three of the Wu patent ""392, the Yen patent ""389, and the Merminod patent ""369 teach biasing the wheel toward the user on only one side of the wheel, a torque results when the user pushes on the wheel of any of these disclosed devices, and significant tilting of the wheel occurs. Thus, the action associated with these switch actuation inputs combines tilting as well as translation, and can be considered semi-tilting.
Minimally-tilting switch actuation mechanisms also exist. For example, U.S. Pat. No. 6,292,113 to Wu (Shown in FIG. 2), U.S. Pat. No. 6,285,355 to Chang, U.S. Pat. No. 6,188,393 to Shu, U.S. Pat. No. 5,530,455 to Cillick et al., and older Microsoft(copyright) INTELLIMOUSE all disclose button-wheels in which the entire wheel mounting moves to achieve switch actuation. In order to enable the movement of the entire mounting, these devices tend to be larger, more complex, and more costly than the device of the Siddiqui reference. In the devices disclosed by the Wu patent ""113, the Chang patent ""355, and older INTELLIMOUSE, these wheel mountings are biased toward the user by one spring located on one side of the wheel. In contrast, in Gillick ""455""s and Shu ""393""s devices, the mountings are biased toward the user on both sides of the wheel. With biasing forces on both sides of the wheel, where user push-type forces are applied, the wheel mounting can respond to user push-type force with motion that is more translation than tilting. With this substantially translational motion, in which translation is the primary action of switch actuation, it is possible to produce tactile force and displacement responses that are more uniform across the width of the wheel. However, this additional biasing force usually increases the size, complexity, and cost of the mechanism beyond that associated with a single biasing force as will be explained later in the disclosure.
Despite these numerous button-wheel designs, the general tilting-shaft button-wheel idea and configuration described by Siddiqui is still currently the most popular commercial button-wheel embodiment. This is largely because button-wheels are mostly used in mice, and the Siddiqui device is a low-cost and low-complexity device that satisfies mouse design criteria.
Mice have minimal space constraints, since they must be at least a minimum external size for ergonomic reasons. This external size leads to internal spaces that are typically much larger than necessary to accommodate the sensors, structures, mechanisms, and electronics associated with conventional mouse features. Faced with this minimal space constraint, conventional mice have focused on minimizing cost and complexity instead of size. Thus, the internal components of mice are usually larger, cheaper, and easier to assemble than those found in more space-constrained input devices, such as PDA touch screens, laptop pointing sticks, and computer touchpads. This minimal space constraint has also affected the development focus of button-wheels in prior art devices. Siddiqui""s device, along with the variations described above, focus on reducing the cost and complexity of the button-wheel, often at the trade-off of increased mechanism size.
Mice also have relatively minimal constraints on uniform displacement and force feedback to the user, which makes tilting and semi-tilting button-wheel devices viable devices. Tilting and semi-tilting systems provide varying displacement and force feedback across the width of the wheel; the wheel shaft acts as a lever arm about the center of tilt and scales the force and displacement feedback as dictated by geometry. However, since the width of the wheel is small compared to its lever arm, the differences in force and displacement tactile feedback along the width of the wheel are small and almost unnoticeable to the user. These minimal uniform feedback constraints have enabled mouse button-wheels to utilize simpler mounting designs and fewer components than if uniform feedback were required.
Unlike mouse button-wheels, many input devices must provide uniform force and displacement feedback. For example, some computer keyboards contained space bars that tilted about their centers. These space bars were unsatisfactory, since they were long enough such that the non-uniform feedback across the width of the space bar were noticeable to the userxe2x80x94some of these space bars even jammed when they were depressed on their left or right edges. In response, keyboard makers introduced a host of different linkages and mechanisms to ensure uniform feedback across the width of the space bar, and space bars that tilted about the center are no longer used.
Although the above observations have highlighted computer mice because button-wheels are most often found in mice, the same observations also apply to any device similar to mice in terms of size and feedback constraints. Examples of such devices include, but are not limited to, trackballs, handheld videogame control pads, and joysticks. However, these minimal constraints on size and feedback will not always apply. For example, as computer mice and similar devices grow in complexity to incorporate features such as wireless communications and force feedback, space constraints will grow tighter.
Existing devices such as Personal Digital Assistants (PDA) and laptops also have very tightxe2x80x94especially height to reduce the overall thickness of the PDA or laptop-space constraints. In addition, devices such as PDAs and laptops may best be served by button-wheels with wider wheels and lower ratios of wheel diameter to wheel width and shaft length to wheel width. These lower ratios help the button-wheels meet tighter space constraints and allow users to manipulate the button-wheels in more ways. Unlike button-wheels for mice, which are usually manipulated by one or two dedicated digits, button-wheels for PDAs and laptops may be located where users can access them with thumbs, multiple fingers, or either hand.
These lower ratios of wheel diameter to wheel width and shaft length to wheel width also mean tighter feedback requirements that make tilting and semi-tilting designs much less desirable. With these lower ratios, a tilting or semi-tilting design would yield a greater difference in force and displacement feedback along the width of the wheel than a similar design targeted for mice. This difference may be noticeable and disturbing to users. At an extreme case for a tilting shaft system, the user may not be able to actuate the button near the center of tilt, or may jam the button-wheel at the end opposite that of the center of tilt. These failure modes are similar to those of space bars that tilted about their centers, and accentuate the importance of uniform force and displacement response in button systems where the component that interacts with the user is relatively wide.
Button-wheels utilizing tilting or semi-tilting designs have a further disadvantage in that they usually need to accommodate a vertical travel height that is greater than that traveled by the wheel during switch actuation. The actual difference is dependent on the lengths of the lever arms from the center of pivot to the wheel and to the farthest pivoting or semi-pivoting point. For example, in a design with a tilting-shaft approach and a wheel mounted equidistant between two bearings, the vertical distance traveled by the section of the shaft within the bearing that does not function as the fulcrum is approximately twice that of the wheel. Mounting the wheel at the section of the shaft that travels the greatest distance during the tilting or semi-tilting switch actuation action (typically one of the end sections of the shaft) may reduce the motion that must be accommodated by the button-wheel during switch actuation. However, this approach also introduces undesirable characteristics associated with a cantilevered-wheel system.
The ideal button-wheel for this set of design criteria associated with applications similar to PDAs and laptops is one that minimizes size (especially height), ensures that no parts of the button-wheel need to travel more than the wheel during switch actuation, and provides uniform force and displacement feedback to the user during switch actuation. The ideal button-wheel also minimally increases the complexity and cost of the button-wheel.
Some prior-art devices do attempt to address some of the tighter space constraints, but they still utilize tilting as the main switch actuation mechanism. For example, U.S. Pat. No. 6,198,057 to Sato et al. (Shown in FIG. 3) and U.S. Pat. No. 6,194,673 to Sato et al. both shrink a tilting-shaft design by utilizing smaller parts and integrating multiple components into one mechanism; for example, the device of Sato ""057 uses smaller mechanical and electrical components, removes the biasing spring and uses the switch as the biasing agent, replaces the optical wheel encoder with a mechanical one, and combines the mechanical encoder, detent, and bearing into one integral part.
Even though these two devices of Sato ""057 and Sato ""673 do shrink the size of the button-wheel noticeably, they do not address the shortcomings of a tilting or semi-tilting mechanism as outlined above. Both devices by Sato ""057 and Sato ""673 must be tall enough to accommodate the greater vertical distance traveled by the end of the shaft opposite from the center of tilt, which is greater than the actual vertical distance traveled by the wheel. In addition, these systems still have an inherently nonuniform tactile response across the width of the wheel.
Another button-wheel design that attempts to fit within the tighter space constraints is U.S. Pat. No. 6,211,474 to Takahashi. Takahashi""s device is similar to the tilting-shaft design described by the Siddiqui patent""661with one exception. The wheel can tilt about the center of the wheel shaft as well as tilt about one of the bearings. Takahashi""s device has the same deficiencies as both of the devices outlined by Sato ""057 and Sato ""673, and is more complex and even less uniform in tactile response to accommodate the additional degree of wheel tilt freedom about the center of the shaft.
A device that attempts to fit within the tight space constraints and does not use shaft tilt to actuate the button is U.S. Pat. No. 6,218,635 to Shigemoto et al. (Shown in FIG. 4). Shigemoto ""635 describes a mechanism in which the entire wheel mounting is located above a switch. When the user pushes on the wheel, the entire wheel mounting tilts about an external axis distinct from and parallel to the wheel axis to actuate the button of the switch. Although this configuration means that the button-wheel only has to accommodate the vertical travel of the wheel, having a moving mounting still results in a larger overall size and probably greater complexity than that associated with a stationary mounting and moving shaft. In addition, the Shigemoto device must also accommodate some horizontal motion of the mounting that is associated with the mounting tilt.
No button-wheel currently exists that fulfills all the design constraints associated with devices such as PDAs and laptops, where tight spaces and uniform tactile feedback are highly desirable. Existing devices hold onto ideas that are more applicable to computer mice, contain features that increase the size of the button-wheel, or introduce more complex and costly mechanisms. The present invention addresses the deficiencies of these prior art approaches.
The disclosure describes a button wheel. The button wheel comprises a support frame including a pair of parallel opposed inner surfaces. A platform is nestably mounted in the support frame. The platform includes a pair of parallel opposed outer surfaces forming a pair of linear bearings with the parallel opposed inner surfaces of the support frame to allow the platform to translate from a biased rest position in a direction parallel to the opposed inner surfaces and the opposed outer surfaces. The button wheel also includes first and second spaced apart mounts fixed to one of the support frame and said platform. The button wheel includes a shaft disposed along an axis and including a first end rotatably engaged in the first mount and a second end rotatably engaged in the second mount. A wheel is mounted on the shaft and a rotation sensor is in operative communication with the wheel. The button wheel also includes a translation sensor coupled between the support frame and the platform.
The disclosure also describes an alternative embodiment of the button wheel. This embodiment comprises a support frame including a flat-spring region and a first mount disposed on the flat-spring region of the support frame. The button wheel includes a second mount spaced apart from the first mount and disposed on the support frame. A translation sensor is mounted in a fixed position with respect to the fixed region of the support frame. The button wheel also includes a shaft disposed along an axis and including a wheel mounted on the shaft and a first end rotatably engaged in the first mount and a second end rotatably and translatably engaged in the second mount so as to allow the shaft to translate with respect to the support frame in a direction substantially perpendicular to the axis to actuate the translation sensor upon the application of mechanical force to the wheel having a component substantially along the direction. The button wheel has a rotation sensor in operative communication with the wheel.
Another button wheel embodiment is described in the disclosure. The button wheel comprises a support frame and first and second spaced apart mounting members mounted to the support frame. A shaft is disposed along an axis and including a first end rotatably engaged in the first mounting member and a second end rotatably engaged in the second mounting member. A first translation limiter is disposed on the shaft proximate to the first end and adjacent to the first mounting member to limit the translation of the shaft along the axis. A second translation limiter is disposed on the shaft proximate to the second end and adjacent to the second mounting member to limit the translation of the shaft along the axis. A wheel is mounted on the shaft and a rotation sensor is in operative communication with the wheel. The button wheel includes a translation sensor coupled between the support frame and the shaft.
Another embodiment is described comprising a support frame and first and second biasing members mounted on the support frame. The button wheel includes first and second spaced apart movable mounting members mechanically coupled to the support frame through the first and the second biasing members. A shaft is disposed along an axis and includes a first end rotatably engaged in the first movable mounting member and a second end rotatably engaged in the second movable mounting member. A wheel is mounted on the shaft. A rotation sensor is in operative communication with the wheel and a translation sensor is coupled between the support frame and the shaft.